If you want to test your pump after changing brushes while it is out of car then the terminal on the side with external rounded curve is the negative terminal (as shown in attached pictures), it is a 12v motor and I tested it using my wifi router's adopter.
Also I used the cotton thread and tie it on the back side of the plate out of the motor to push the brushes in before putting the plate back in. I was not able to pull the thread out of the pump after closing as that was my actual plan. I had to pull the plate back a little and wiggle it around to move the thread out of the way as the pump was not working in the beginning.
Actually there is a rubber o ring around the plate to keep the motor water proof/resistant the rubber will make tight contact with walls of motor and will not let the thread come out at all.
May be if I had kept the plate a little out before pulling the thread out it might have fully came out, it is easily possible to keep the back plate out at least by 3mm while still keeping the brushes engaged in rite place.
May be if you oil the whole thread it might pull out easily. Or may be use some stronger thread but that might cut the rubber o ring (making it non water proof) while being pulled out.
See the thread information here
https://www.fordmpv.com/smf2/ford-galaxy-common-faults-and-problems/galaxy-replacing-the-run-on-pump-brushes-(tdi-and-v6)/Also there is a narrow channel already left in the wall that runs on the under side of brushes, this channel can be used easily for running your thread.
I have not tried opening the front side of the pump may be it is not that difficult if that can be done may be we can push the whole motor armature down a bit to engage in between the brushes and then slowly pushing the plate in while keeping the finger (with coin in between) on the other side to not let the armature quickly jump in due to magnetic force in this way we can avoid this whole business of threads.
Someone mentioned using water freeze method, I do not feel comfortable with that as this motor is intentionally made water proof. So freezing will leave some water inside the motor may be if we keep the plate up by 3mm or so and use hot air from hair drier ect. to make it dry etc.
If anyone has any other ideas then please share.
